A young shepherd, Corydon, is driven out of his village because of his unusual appearance and then captured and put on display as a monster. Alongside him in the traveling freak show are Medusa, the Minotaur, the Sphinx, and other classical beasts. When Corydon helps these monsters to escape their cages, they scatter to seek peace and solitude away from prying eyes. But then an army of "heroes" arrives hoping to win glory by killing the monsters, and Corydon must unite these unloved and unlikely allies to fight for their survival and for their island home.